Determination of Optical Characterization of the CdZnSe2xTe2(1-x) Thin Films Deposited by Spray Pyrolysis Method

CdZnSe2xTe2(1-x) thin films for different composition parameters ‘x’ have been deposited on large substrate area (glass plates) by the spray pyrolysis method which is simple, inexpensive and economical at 300o C substrate temperature. The main objective of this study is to characterize the thin films grown by measuring their optical properties which include Absorbance (A), Transmittance(T), Reflectance(R), Absorption coefficient( ), Band gap energy (Eg), Refractive index (n), Extinction coefficient (k), Dielectric constant ( ),(real and imaginary parts) and Variation of these properties with composition parameter. From the optical transmission and reflection spectra, absorption coefficients were calculated. Band gap energy were determined from absorbance measurements in visible range using Tauc theory. Band gap energy values are found to lie in the range 2.04-2.52 eV for the films with composition parameter, x= 0 to 1. It shows that the main transition at the fundamental absorption edge is a direct allowed transition. The values of optical parameters obtained by this method are suitable for many scientific studies and technical applications.